Containers for many substances, in particular medicines, are required by governmental regulation to be child-resistant. The typical child-resistant closure engages an associated container with releasable locking means, in such a manner that a relatively complex manipulation is required to remove the child-resistant closure from the container. Several types of child-resistant closures are illustrated in U.S. Pat. No. 3,830,391 to Uhlig. In one form of child-resistant closure, the skirt must be squeezed inwardly while the closure is simultaneously rotated, to disengage the locking means. In another form, the closure must be axially pushed downwardly relative to the container while simultaneously being rotated. In still another form, a resilient flange on either the closure skirt or the container neck must be deflected manually from engagement with a locking lug, while the closure is rotated.
While such closures may be effective in preventing access to container contents by children, they are inconvenient to many users. Frequently, adult users, such as those with arthritis, are unable to open child-resistant closures on medicine containers. While it is possible for a customer to request a medicine container having a simple, non child-resistant closure, such a choice leaves the customer without an option to later reseal the container with a child-resistant closure, should he so desire.
U.S. Pat. Nos. 3,865,267 and Re. 29,779 disclose an integral, reversible closure having two closure portions, one with a child-resistant feature and the other without. The reversible closure is oriented on the container such that the desired closure portion seals the container opening.